Why did Japan surrender in World War II?

There is contentious debate among scholars about why Japan surrendered in World War II. Some believe the Aug. 15, 1945, declaration was the result of the atomic bombs dropped on Hiroshima and Nagasaki.

It’s possible that these finally pushed Emperor Hirohito (posthumously called Emperor Showa) to break the deadlock in the Supreme War Council and accept the terms of the Potsdam Declaration for unconditional surrender issued by the Allied leaders on July 26, 1945. In that declaration, there was a promise of “prompt and utter destruction” if the armed forces of Japan didn’t surrender. The use of weapons of mass destruction causing the incineration of large swaths of Hiroshima and Nagasaki in quick succession backed up that threat, highlighting the futility of continuing the war. Emperor Hirohito’s intervention on the side of those favoring capitulation was crucial to winning over those hardliners who didn’t. In this narrative, the dawning of the nuclear age brought peace. It also allowed military leaders to save face, since they could claim that the war was not lost on the battlefield, and agree to surrender to spare the Japanese people from more suffering.

This meant abandoning ketsu-go, the strategy of fighting one last decisive battle intended to inflict so many casualties on a war-weary America that it would relax its demands for unconditional surrender and negotiate a peace. This would, at a minimum, safeguard the Emperor, and potentially preserve the armed forces and shield them from prosecution for war crimes. This strategy was affirmed in June 1945 as the gruesome and bloody Battle of Okinawa was winding down. Reinforcements had been transferred from Manchuria to bolster the defense of Kyushu where the U.S. was expected to attack next.

In February 1945, Joseph Stalin met with Allied leaders in Yalta, promising to attack Japan three months after Germany’s surrender. He kept his promise, and Soviet troops invaded Manchuria in the wee hours of Aug. 9 before the Nagasaki bombing later that day. This came as a shock to Japanese leaders who had been trying throughout July that year to engage the Soviets as brokers in a peace deal with the Allies.

Soviet entry into the war was an alarming development for a military leadership that vowed to keep fighting to save the Emperor. The fate of the czar at the hands of communists, and prospects for a punitive Soviet occupation, influenced the calculus of surrender.

In February 1945, the Japanese military conducted a survey that concluded that Japan could not win the war. But they were not squeamish about the suffering of the Japanese public — more than 60 Japanese cities were subjected to extensive firebombing in 1945, displacing, maiming and killing several hundred thousand civilians. Military leaders could not contemplate the ignominy of surrender, so they compelled their nation to continue fighting a war that was already lost, subjecting the Japanese to horrific suffering that they could have ended far sooner.

Historian Tsuyoshi Hasegawa, in his 2005 book “Racing the Enemy,” provides compelling evidence that the Pacific War ended due to the entry of the Soviets, not the atomic bombings. Having tasted defeat at the hands of the Soviets twice in the late 1930s in Manchurian border clashes, the generals knew that the new front meant further resistance was futile.

Sheldon Garon, a professor of history at Princeton University, takes issue with Hasegawa’s contention that the military was insouciant about Japanese suffering and ready to fight to the last civilian. Recently, Garon gave a talk in Tokyo about an ongoing book project focusing on how the war was lost for Germany and Japan.

He argues that the U.S. was surprised by Japan’s sudden surrender, noting that by Aug. 19, 1945, America would have had three more atomic bombs ready and had six more in production — it did not anticipate a swift end.

According to Garon, the Japanese military was deeply concerned by worsening conditions in Japan because they were undermining the war effort. Authorities, for example, planned the evacuation of a few hundred thousand school children to spare them the urban conflagrations, but were not prepared for the mass exodus of adults who bailed because they knew the military could not protect them. Roads out of Tokyo were clogged with these refugees: 8.5 million fled Japanese cities in the final five months of war, paralyzing transport networks.

According to Garon, these acts of sabotage also meant that an orderly society was no longer obeying orders, responding to accumulating signs of impending defeat. Alas, many of these unlucky refugees fled to smaller cities, and thus were subject to more bombings as America moved onto second-tier targets. The U.S. dropped leaflets warning of impending strikes, and then delivered, stoking fear and undermining faith in the government.

Officials were also demoralized by Germany’s surrender, and the horrific fight to the end that Adolf Hitler insisted on, subjecting his people and cities to a relentless pounding.

Garon observes that the Germans fought like samurai, sacrificing all even when they knew it was for a losing cause. While much is made of Japanese authorities training women and children to resist U.S. invaders with bamboo staves, Garon notes that none ever did so. In contrast, Germany took desperate measures, resorting to full mobilization and deploying these untrained conscripts to battlefields where many died or were injured.

Japan’s diplomats in Europe were shocked by the devastation of Germany and conveyed their concerns about Hitler’s “fighting to the finish” strategy. They advised against emulating the Germans, and thus implicitly counseled surrender for the national interest. But finding an exit with dignity proved elusive.

Garon attributes Japan’s delayed surrender to military intransigence and diplomatic incompetence, a dithering that subjected Japan to needless devastation.

Finally, it was the Soviet entry into the war and the atomic bombings that precipitated a hasty surrender. But it was overdue because the signs of defeat, including a devastating series of setbacks on the home front, had been gathering for some time: endless fire bombings, growing shortages of food due to the U.S. blockade “Operation Starvation,” bereaved families and the subversion of people voting with their feet. There was no appetite for suffering the fate of the Nazis or subjecting the nation to more nightmarish ruination.

As the public — no longer willing to endure — soured on the war, what choice did the Emperor and his advisers have if the Imperial Household was to survive?

Jeff Kingston is the director of Asian Studies, Temple University Japan.